A mayor-elect from the Institutional Revolutionary Party that scored a comeback in recent elections was found shot dead on Sunday with an aide in northern Mexico, officials said.
"The lifeless body of mayor-elect Edgar Morales was found in a van this morning" in the town of Matehuala in San Luis Potosi state, a spokeswoman for the local prosecutor's office told AFP by telephone. The second body was identified as Juan Francisco Hernandez, Morales's campaign manager.
A man who survived the attack with no injuries told police that unidentified assailants attacked the three men as they left a party.
San Luis Potosi has been rocked in recent days by a wave of violence attributed to drug cartels, including the discovery of 14 bodies inside a van on Thursday.
The Zetas cartel, founded in the mid-1990s by military deserters, is active in San Luis Potosi and surrounding states. It is considered one of Mexico's most powerful and violent drug gangs.
Morales had been elected in the July 1 elections that also earned Enrique Pena Nieto the presidency.
Both hail from the Institutional Revolutionary Party, or PRI, which ruled Mexico under an authoritarian regime for more than seven decades, until it was voted out in 2000.
Morales joins a string of other mayors targeted by drug gangs seeking to dominate local affairs. At least six were killed across Mexico in 2011, and 15 the year before.
More than 50,000 people have been murdered since December 2006, when outgoing President Felipe Calderon launched a military offensive against drug cartels -- whose failure analysts link to Calderon's defeat in the July polls.
Pena Nieto has promised a "new strategy" and also pledged to wage his battle "without pacts or truces" -- a nod to the tactic his party was previously known for, of looking the other way while drugs were sent north of the border as long as the cartels did not commit violence within Mexico.
However, the incoming president has yet to offer much detail of his plans.